Weft take-up mechanism



July 11, 1967 K. J. HALL 3,330,304

WEFT TAKE-UP MECHANISM Filed Sept. 24, 1965 2 Sheets-Sheet 1 FIG. 2

INVENTOR KENNETH J. HALL BY waflfmw 7' ATTORNEY y 11, 1967 K. J. HALL 3,330,304;

WEFT TAKE-UP MECHANISM Filed Sept. 24, 1965 2 Sheets-Sheet 2 no 23 v INVENTOR KENNETH J. HALL b MWJ I ATTORNEY United States Patent 3,330,304 WEFT TAKE-UP MECHANISM Kenneth J. Hall, Worcester, Mass., assignor to Crompton & Knowles Corporation, Worcester, Mass., :1 corporation of Massachusetts Filed Sept. 24, 1965, Ser. No. 489,870 4 Claims. (Cl. 139122) This invention relates to a weft take-up mechanism for looms operating with stationary weft supplies, and more particularly to looms of this type where weft is introduced into the warp sheds by a shuttle having grippers to which the weft is attached, as shown for instance in US. Patents Nos. 2,817,367 and 3,014,505. Since a weft is cut and re-inserted into a shuttle gripper for each pick, it is necessary to maintain constant tension and to prevent the weft from becoming slack in the vicinity of shuttle gripping.

Various types of spring wires have been used to take up slack in the weft but their disadvantage lies in the dimculty of controlling the amount of spring-back and vibration, sometimes resulting in a tangling of the weft. Mechanical slack take-up devices have been used which prove to be cumbersome and unreliable, as the mechanical motion of pulling back has to be of the correct amount and has to occur at the correct time when slack is likely to occur.

It is an important object of the present invention to provide a spring biased slack take-up mechanism which will not have the disadvantage of the aforementioned mechanical motions and spring wire take-ups, and be capable of taking up slack weft smoothly, evenly and under relatively constant tension.

Another object of the invention is to provide a slack take-up mechanism which will allow the shuttle to draw weft under less tension than is normally required for weft insertion, during the critical state of shuttle picking where, due to inertial forces, the weft is most likely to be pulled out of the shuttle grippers.

A still further object of the invention is to provide said slack take-up mechanism with means to adjust the amount of tension by which slack is taken up.

Other objects and the details of that which is novel will be clear from the following description and claims taken with the accompanying drawings in which is illustrated an example of a device embodying the present invention.

In the drawings:

FIGURE 1 is a view diagrammatically illustrating the invention,

FIGURE 2 is a plan view of the weft take-up mechanism,

FIGURE 3 is a front elevation looking in the direction of arrow 3, FIGURE 2,

FIGURES 4-7 are diagrammatic views illustrating the operation of the invention.

Referring to FIGURE 1 the weft take-up mechanism, generally indicated at 10, is shown disposed between an outside weft package 12 and a weft inserting mechanism generally indicated at 14. The weft W extends from package 12 through a tensioning portion 16 of the take-up mechanism which can be any standard type friction tension and then through the take-up portion 18 of the takeup mechanism 10, the weft then extends to the weft inserting mechanism 14. Weft mechanism 14 includes a weft inserter or shuttle 20 and a presenter 22. The weft is always connected to one or the other, to the shuttle during a weft inserting operation and to the presenter between a pick-up and presenting operations, see US. Patent No. 3,014,505.

Referring to FIGURES 2 and 3, the take-up portion 18 includes a pair of spaced plates 24 and 26 with guides 23 and 25 respectively in their upper portion thereof. Ex-

tending between plates 24 and 26 are two spaced pivot rods 28 and 30. Rod 28 has pivotally mounted thereon a pair of spaced arms 32 and 34 each having a curved outer portion 36 which begins from a point 38 and ends at a point 40, after which there is a reverse curve forming a rounded notch or thread engaging portion 42. A lever 44 is pivotally mounted on pivot rod 30. Pivotally attached at 45 to one end of lever 44 are a pair of connecting rods 46 and 48 pivotally attached at points 50 and 52 on arms 32 and 34 respectively. Also mounted on pivot rod 30 is a coil spring 54 attached at one end to rod 30 and at its other end to lever 44. Spring 54 has a tendency to rotate lever 44 in a counter clockwise direction around rod 30 as viewed in FIGURE 3. This action through connecting rods 46 and 48 tends to rotate arms 32 and 34 in opposite directions around pivot rod 28 as indicated by arrows a and b, FIGURE 3.

In operation, the weft W which extends from tension portion 16 passes through guide 23, around weft engaging section 42 on take-up arm 34 to the weft engaging section 42 in arm 32 around which it extends to and through guide 25 to weft inserting mechanism 14.

The previously mentioned curved portions 36 on arms 32 and 34 operate as a self threading feature when a weft is introduced through the take-up mechanism either in an initial threading up or rethreading operation. In threading, a weft is drawn through guides 23 and 25 and held taut while lever 44 is rotated counter clockwise as viewed in FIGURE 3, drawing takeup arms 32 and 34 toward each other until points 40 pass one another in directions opposite that indicated by arrows a and b. As take-up arms 32 and 34 move past each other their points 38 slip under the tightly held weft which begins to ride up over curves 36 which are at an increasingly greater distance from pivot rod 28 from points 38 to points 40. After points 40 pass each other the weft snaps into weft engaging portions 42 so that upon release of lever 44, arms 32 and 34 will move away from each other and the weft will assume the position shown in FIGURE 2 providing that the end of the weft being held is released and that there was enough weft being held to be taken up in the manner shown. The end of the weft leading from guide 25 can then be attached to weft inserting mechanism 14.

After the weft take-up mechanism is threaded and the weft attached to the weft inserting mechanism, it will operate in the following manner:

Referring to FIGURES 4-7 there is shown an example of a weft inserting operation which produces a great deal of slack and for which the invention is particularly useful.

As shown in FIGURE 4 the weft inserter 20 is in a position of just having been picked-out from the lefthand side of the loom and is beginning its flight through the shed. Spring 54 is such that arms 32 and 34 create less tension on the weft than tension portion 16. Due to this difference in tension, arms 32 and 34 are drawn together as the shuttle is picked out drawing weft from what was distributed through the take-up arms. After arms 32 and 34 are brought together, the shuttle then draws weft from package 12 through tension portion 16. The tension portion 10 is set to give the normal operating tension to the weft. Since, during the most critical stage when the shuttle is first picked out and, due to inertial forces, is most likely to lose the weft, it draws weft from the take-up arms under less than normal tension, thus alleviating somewhat this condition of likely weft loss. In FIGURE 6, the shuttle (not shown) has arrived at the other end of the loom and the weft presenter 22 is shown retrieving the weft at the edge of the cloth where it has just been cut. The presenter 22, after retrieving the weft as shown in FIGURE 6 must then move back to its presenting position as shown in FIGURE 7 to be ready to 3 transfer the end of the weft to the inserter or shuttle 20 when it comes back to the dotted line position at the lefthand side or" the loom. Due to the motion of presenter 22 from is position in FIGURE 6 to its position in FIG- URE 7 slack would normally develop in the weft to the extent of the distance between these two points. Due to the present invention however, slack is never allowed to develop, as take-up arms 32 and 34 begin to move away from each other in the direction of the arrows shown in FIGURE 3 as soon as presenter 22 begins to move to the left from its position in FIGURE 6. As shown in FIGURE 7, arms 32 and 34 have taken up the full amount of weft equal to the traveled distance of presenter 22. V

As shown in the drawings there is employed two take-up arms but only one or more than two may be used depending on Weaving conditions. It has been found, in the present application of the take-up'mechanism, that two arms as shown, both moving in synchronism due to connecting rods 46 and 48, provide smooth trouble-free operation of the take-up mechanism.

The tension applied to the take-up arms may be varied by means shown in FIGURES 2 and 3. In these figures there is shown a series of detent holding means 60 which are capable of engaging a detent 62 connected to the end of pivot rod 30 which extends beyond plate 26 at 64. Holding means '60 are shown as a series of teeth extending from plate 26, radially disposed around the pivoted center of pivot rod 30. By moving detent 62 to any of the teeth 60,'rod 30 will be turned, either winding or unwinding coil spring 54 depending on the direction rod 30 is turned. The winding or unwinding of coil spring 54 will increase or decrease the tension on arms 32 and 34. Although the detent holding means shown are teeth, the invention is not limited to this as other forms of holding means may be utilized such as a series of holes in co- 7 operation with an appropriately shaped detent.

As will be evident from the foregoing description, certain aspects of the invention are not limited to the particular details of construction of the example illustrated,

. and it is contemplated that various and other modifications and applications of the invention will occur to those skilled in the art. It is therefore the intention that the appended claims shall cover such modifications and ap- 4 plications as do not depart from the true spirit and scope of the invention.

What is claimed and desired to be secured by Letters Patent of the United States is':

1. In a loom having an outside weft supply and a weft inserting mechanism, a slack take-up mechanism disposed in the path of the yarn between said supply and said weft inserting mechanism, said take-up mechanism comprising:

(a) spaced weft guide members;

(b) first and second take-up'arms pivotally mounted between said spaced guide members so as to pivot about a common axis; and

(c) a spring operatively connected to said first arm at a point spaced from one side of said axis and to said second arm at a point spaced from the other side of saidaxis whereby force exerted by said spring in one direction causes said arms to pivot about said axis in opposite directions.

2. In a loom as set forth in claim 1 wherein the spring is connected to said arms by means of a pivoted lever and linkages between said lever and said arms.

3. In a loom as set forth in claim 1 wherein means are provided to adjust the force exerted by the spring.

4. In a loom as set forth in claim 1 wherein each of said take-up arms is provided with a curved outer portion so shaped and so disposed as to cam a' taut weft into a weft engaging portion on one side of said arm as said arms move past the weft in a direction opposite from that in which it moves to take-up slack weft.

References Cited 7 V UNITED STATES PATENTS 1,021,919 4/1912 Crawford 242-154 1,064,292 6/1913 Crawford 242154 1,923,954 8/1933 Rossmann 139-125 2,950,877 8/1960 Bennett 242154 3,194,276 7/1965 Krukenis et al. 139-212 FOREIGN PATENTS 504,345 5/1960 Italy.

MERVIN STEIN, Primary Examiner.

H. S. JAUDON, Assistant Examiner. 

1. IN A LOOM HAVING AN OUTSIDE WEFT SUPPLY AND A WEFT INSERTING MECHANISM, A SLACK TAKE-UP MECHANISM DISPOSED IN THE PATH OF THE YARN BETWEEN SAID SUPPLY AND SAID WEFT INSERTING MECHANISM, SAID TAKE-UP MECHANISM COMPRISING: (A) SPACED WEFT GUIDE MEMBERS; (B) FIRST AND SECOND TAKE-UP ARMS PIVOTALLY MOUNTED BETWEEN SAID SPACED GUIDE MEMBERS SO AS TO PIVOT ABOUT A COMMON AXIS; AND (C) A SPRING OPERATIVELY CONNECTED TO SAID FIRST ARM AT A POINT SPACED FROM ONE SIDE OF SAID AXIS AND TO SAID SECOND ARM AT A POINT SPACED FROM THE OTHER SIDE OF SAID AXIS WHEREBY FORCE EXERTED BY SAIS SPRING IN ONE DIRECTION CAUSES SAID ARMS TO PIVOT ABOUT SAID AXIS IN OPPOSITE DIRECTIONS. 